Architectural Acoustics Illustrated

Architectural Acoustics Illustrated translates the quantitative and qualitative content of acoustics into the graphic language of architecture. This highly-visual guide includes over 350 illustrations that outline the physics of sound and the best design practices for limiting or mitigating noise in buildings by using the latest in materials and techniques. Each chapter includes a summary checklist of design guidelines to help prevent mistakes and oversights, and the Instructor's website offers video animations demonstrating acoustical concepts. Designed as a "first look" at the interaction of sound and space, the book explains the principles of architectural acoustics and their practical applications, providing a comprehensive guide for designing with acoustics in mind.

Architectural acoustics is more than just concert halls ? it may determine building placement, division of interior space, exterior construction, and even siting. When addressed early in the design process, the resulting space can be free of unwanted sound and promote good hearing; if left unaddressed, the problems with the space can lead to lawsuits and costly post-construction remediation. Architectural Acoustics Illustrated helps designers solve most acoustical problems in advance, by enabling readers to:

• Understand the physical science underlying the behavior of sound
• Consider the interactions of sound and space in the initial design approach
• Mitigate building sounds such as those produced by HVAC and plumbing with early design planning
• Design spaces for listening, and incorporate acoustics best practices into every plan

The highly visual format of the book helps readers grasp complex concepts quickly, and thorough discussion of each concept's real-world application ties the science directly into the design process. All design professionals need to have a fundamental understanding of acoustics, and Architectural Acoustics Illustrated is a comprehensive, practical guide in an easy-to-read format.

Acknowledgments xi

Introduction xiii

1. Basic Theory 1

Sound Level 2

Sound Level 2

Source Path Receiver 4

Measuring Sound Level 5

Measuring Sound Level 8

Multiple Sound Sources 9

Decibel Addition 10

Sound Propagation 11

Sound Propagation 11

Directivity 12

Sound Frequency 13

Frequency 13

Octave Bands 17

Sound Level Perception and Frequency 19

A‐Weighted Decibels 20

The Special Case of Low‐Frequency Sound 22

2. Sound Absorption 25

Principles of Absorptive and Reflective Surfaces 26

Absorption Coefficient 27

Types of Sound Absorbers 29

Room Constant 33

Room Average Absorption 33

Noise Reduction Coefficient (NRC) 36

Sound Absorption Data 38

3. Room Acoustics 57

Room Acoustics Qualities 58

Impulse Response 58

Reverberance 60

Optimal Reverberation Time 65

Clarity 66

Variable Acoustics 70

Reverberation Time Calculation Checklist 74

Room Shaping for Speech and Music 75

Loudness 76

Balconies 80

Sightlines 82

Warmth 83

Concert Hall Types 85

Spatial Impression 87

Intimacy 94

Diffusion 95

Theater Planning 97

Stage Acoustics 97

Orchestra Pits 101

What Makes a Good Room for Music? 102

Performance Venue Seats 106

Acoustic Defects 109

Acoustic Defects 109

Performance Venues 114

Room Acoustics History 114

Performance Venues to Visit 117

Design Checklists 118

Rooms for Unamplified Music Performance Checklist 118

Other Types of Rooms Checklist 119

Sound System Design 123

Electronic Sound Reinforcement 123

4. Noise Control 131

Sound Isolation Principles 132

Apartment Layout Graphic Quiz 132

Flanking 133

Flanking Graphic Checklist 134

Flanking Noise Checklist 134

Measures of Airborne Sound Isolation 140

Transmission Loss (TL) 140

Sound Transmission Class (STC) 142

How to Measure Sound Transmission Class (STC) 144

Target STC Ratings 146

Noise Reduction (NR) 147

Achieving Higher Acoustical Privacy 148

Background Noise 152

Background Noise 152

Noise Criteria (NC) 153

Speech Intelligibility and Noise 155

Open‐Plan Office Acoustics 157

Sound Transmission Loss Data 162

Noise Reduction Example Problem 175

Air‐Structure‐Air Flanking 178

Acoustic Privacy Checklist 179

Apartment Layout Quiz Answer 180

Door and Window Sound Isolation 182

Doors 182

Noise Isolation and Windows 184

Impact Noise 185

Impact Noise Isolation 185

How to Measure IIC 190

Impact Noise Checklist 192

Recommended Floor‐Ceiling Assemblies 195

Resiliently Mounted Room Surfaces 197

Community Noise 202

Principles of Community Noise 202

Building‐in‐Building Design 202

Noise Sources 204

Community Noise Research 207

Community Noise Example Problem 208

Outdoor Barriers 209

Outdoor Barriers Checklist 210

Outdoor Barrier Example Problem 212

Wind Turbine Noise 214

Community Noise Checklist 215

Mechanical System Noise 217

Principles of Mechanical System Noise 217

Ducted Fan Noise 220

Mechanical Room Graphic Checklist 224

Ducted Air Turbulence Noise 225

Vibration Isolation 229

Mechanical Noise Checklist 232

Plumbing Noise 237

Isolating Pipes from Structure 238

Plumbing Noise Checklist 239

Index 243

MICHAEL ERMANN is an associate professor at Virginia Tech's School of Architecture + Design, and a past undergraduate architecture program co-chairman. He teaches architectural acoustics, design studio, and environmental building systems. Prior to joining the VT faculty, Professor Ermann was an acoustical consultant at Artec in New York, NY and Siebein Associates in Gainesville, FL.